Casuarina equisetifolia leaf litter suppresses germination of understory plants using a biochemical means or allelopathy. This is one reason it can be such a damaging invasive species in places outside its native range.

Casuarina equisetifolia is an evergreentree growing to 6–35 m (20–115 ft) tall. The foliage consists of slender, much-branched green to grey-green twigs 0.5–1 mm (0.020–0.039 in) diameter, bearing minute scale-leaves in whorls of 6–8. The flowers are produced in small catkin-like inflorescences; the male flowers in simple spikes 0.7–4 cm (0.28–1.57 in) long, the female flowers on short peduncles. Unlike most other species of Casuarina (which are dioecious) it is monoecious, with male and female flowers produced on the same tree. The fruit is an oval woody structure 10–24 mm (0.39–0.94 in) long and 9–13 mm (0.35–0.51 in) in diameter, superficially resembling a conifer cone made up of numerous carpels each containing a single seed with a small wing 6–8 mm (0.24–0.31 in) long.[2][14]

Casuarina is widely used as a bonsai subject, particularly in South-east Asia and parts of the Caribbean. Indonesian specimens and those cultivated in Taiwan are regarded among the best in the bonsai world. The wood of this tree is used for shingles, fencing, and is said to make excellent hot-burning firewood. Among the islands of Hawaii, Casuarina are also grown for erosion prevention, and in general as wind breaking elements.[citation needed]

The legendary miraculous spear Kaumaile came with the hero Tefolaha on the South Pacific island Nanumea. He fought with it on the islands of Samoa and Tonga. As Tefolaha died, "Kaumaile" went to his heirs, then to their heirs, and on and on - 23 generations. It is about 1.80 meters long and about 880 years old and the tree was cut on Samoa.[16]

The Casuarina leaves are usually used for ornamental purposes in the urban region.[citation needed]

Other than ornamental purposes, the Casuarina was also explored in for its potential in remediation of textile dye wastewater. The Casuarina leaves was found to useful as adsorbent material for the removal of textile dyes such as reactive orange,16[17] Rhodamine B,[18] methylene blue, malachite green [19] and methyl violet 2b.[20] Similarly the Casuarina dried cone was also reported to be able to remove Rhodamine B,[21] and methyl violet 2b.[22] The Casuarina bark was reported to able to remove methylene blue.[23] Even the Casuarina seed was also found to be useful in dye removal of neutral red and malachite green.[24][25] The carbon derived from the cones of Casuarina was found to be good adsorbent for the landfill leachate,[26] while another laboratory also reported good adsorbent for copper ions from aqueous solution.[27]